There have been many attempts in pharmaceutical industries and academia to improve the pharmacokinetic characteristics of anti-tumor small-molecule drugs by conjugating them with large molecules, ...such as monoclonal antibodies, called ADCs. In this context, albumin, one of the most abundant proteins in the blood, has also been proposed as a large molecule to be conjugated with anti-cancer small-molecule drugs. The half-life of albumin is 3 weeks in humans, and its distribution to tumors is higher than in normal tissues. However, few studies have been conducted for the in vivo prepared albumin-drug conjugates, possibly due to the lack of robust bioanalytical methods, which are critical for evaluating the ADME/PK properties of in vivo prepared albumin-drug conjugates. In this study, we developed a bioanalytical method of the albumin-conjugated MAC glucuronide phenol linked SN-38 ((2S,3S,4S,5R,6S)-6-(4-(((S)-4,11-diethyl-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano 3',4':6,7 indolizino 1,2-b quinolin-9-yl)oxy)methyl)(2 (methylsulfonyl)ethyl)carbamoyl)oxy)methyl)-2-(2-(3-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-N-methylpropanamido)acetamido)phenoxy)-3,4,5-trihydroxytetra-hydro-2H-pyran-2-carboxylic acid) as a proof-of-concept. This method is based on immunoprecipitation using magnetic beads and the quantification of albumin-conjugated drug concentration using LC-qTOF/MS in mouse plasma. Finally, the developed method was applied to the in vivo intravenous (IV) mouse pharmacokinetic study of MAC glucuronide phenol-linked SN-38.
The purpose of this study is to investigate the difference of in vitro-in vivo correlation of α-amanitin from clearance perspectives as well as to explore the possibility of extra-hepatic metabolism ...of α-amanitin. First, a liquid chromatography-quadrupole-time-of-flight-mass spectrometric (LC-qTOF-MS) method for α-amanitin in rat plasma was developed and applied to evaluate the in vitro liver microsomal metabolic stability using rat and human liver microsomes and the pharmacokinetics of α-amanitin in rat. The predicted hepatic clearance of α-amanitin in rat liver microsomes was quite low (5.05 mL/min/kg), whereas its in vivo clearance in rat (14.0 mL/min/kg) was close to the borderline between low and moderate clearance. To find out the difference between in vitro and in vivo metabolism, in vitro and in vivo metabolite identification was also conducted. No significant metabolites were identified from the in vivo rat plasma and the major circulating entity in rat plasma was α-amanitin itself. No reactive metabolites such as GSH-adducts were detected either. A glucuronide metabolite was newly identified from the in vitro liver microsomes samples with a trace level. A semi-mass balance study was also conducted to understand the in vivo elimination pathway of α-amanitin and it showed that most α-amanitin was mainly eliminated in urine as intact which implies some unknown transporters in kidney might play a role in the elimination of α-amanitin in rat in vivo. Further studies with transporters in the kidney would be warranted to figure out the in vivo clearance mechanism of α-amanitin.
Itching is an unpleasant sensation that provokes the desire to scratch. In general, itching is caused by dermatologic diseases, but it can also be caused by systemic diseases. Since itching hampers ...patients' quality of life, it is important to understand the appropriate treatment and pathophysiology of pruritus caused by systemic diseases to improve the quality of life. Mechanisms are being studied through animal or human studies, and various treatments are being tested through clinical trials. We report current trends of two major systemic diseases: chronic kidney disease and cholestatic liver disease. This review summarizes the causes and pathophysiology of systemic diseases with pruritus and appropriate treatments. This article will contribute to patients' quality of life. Further research will help understand the mechanisms and develop new strategies in the future.
Maintaining optimal blood inventory levels in hospitals is important to prevent blood shortage and wastage. We aimed to provide an efficient blood inventory management strategy for hospital blood ...banks nation-wide by comparing the current use of 5-day issuable stock (IS) with Lim's IS as a novel target IS.
The average and CV of daily usage (DU) were calculated from information entered into Korea's Blood Management System by 194 participating hospitals in 2019 and 2020. Using these data, Lim's IS was calculated by determining the simulated annual average blood shortage day nearest to 1 for each blood group in each hospital. The 5-day IS (5IS) was estimated by multiplying the average DU in 2018 by five to count the shortage days in 2019.
The average DU (0.3-231.3 units) and corresponding CV (0.33-7.14) in the participating hospitals were inversely proportional (r=-0.699 to -0.695). The hypothetical averages of 5IS and Lim's IS were 27.0±41.2 and 24.7±20.8, respectively (
=0.006). The shortage days for 5IS and Lim's IS were 8.9±22.7 and 1.0±1.9, respectively (
<0.001).
While 5IS was unacceptable for universal application, Lim's IS remained near one shortage day and is considered more efficient than 5IS. Hospitals should implement indicators that consider DU and its variations. This is the first study to introduce Lim's IS as an indicator of optimal blood inventory, and the data are expected to provide guidance for effective blood inventory management nationwide, particularly during blood shortages.
We compared the gut microbial populations in 100 women, from rural Ghana and urban US 50% lean (BMI < 25 kg/m
) and 50% obese (BMI ≥ 30 kg/m
) to examine the ecological co-occurrence network topology ...of the gut microbiota as well as the relationship of short chain fatty acids (SCFAs) with obesity. Ghanaians consumed significantly more dietary fiber, had greater microbial alpha-diversity, different beta-diversity, and had a greater concentration of total fecal SCFAs (p-value < 0.002). Lean Ghanaians had significantly greater network density, connectivity and stability than either obese Ghanaians, or lean and obese US participants (false discovery rate (FDR) corrected p-value ≤ 0.01). Bacteroides uniformis was significantly more abundant in lean women, irrespective of country (FDR corrected p < 0.001), while lean Ghanaians had a significantly greater proportion of Ruminococcus callidus, Prevotella copri, and Escherichia coli, and smaller proportions of Lachnospiraceae, Bacteroides and Parabacteroides. Lean Ghanaians had a significantly greater abundance of predicted microbial genes that catalyzed the production of butyric acid via the fermentation of pyruvate or branched amino-acids, while obese Ghanaians and US women (irrespective of BMI) had a significantly greater abundance of predicted microbial genes that encoded for enzymes associated with the fermentation of amino-acids such as alanine, aspartate, lysine and glutamate. Similar to lean Ghanaian women, mice humanized with stool from the lean Ghanaian participant had a significantly lower abundance of family Lachnospiraceae and genus Bacteroides and Parabacteroides, and were resistant to obesity following 6-weeks of high fat feeding (p-value < 0.01). Obesity-resistant mice also showed increased intestinal transcriptional expression of the free fatty acid (Ffa) receptor Ffa2, in spite of similar fecal SCFAs concentrations. We demonstrate that the association between obesity resistance and increased predicted ecological connectivity and stability of the lean Ghanaian microbiota, as well as increased local SCFA receptor level, provides evidence of the importance of robust gut ecologic network in obesity.
Parkinson's disease is one of the most common neurodegenerative diseases. Adenosine regulates the response to other neurotransmitters in the brain regions related to motor function. In the several ...subtypes of adenosine receptors, especially, adenosine 2A receptors (A
Rs) are involved in neurodegenerative conditions. ZM241385 is one of the selective non-xanthine A2AR antagonists with high affinity in the nanomolar range. This study describes the in vitro and in vivo pharmacokinetic properties of ZM241385 in rats. A liquid chromatography-quadrupole time-of-flight mass spectrometric (LC-qToF MS) method was developed for the determination of ZM241385 in rat plasma. In vivo IV administration studies showed that ZM241385 was rapidly eliminated in rats. However, the result of in vitro metabolic stability studies showed that ZM241385 had moderate clearance, suggesting that there is an extra clearance pathway in addition to hepatic clearance. In addition, in vivo PO administration studies demonstrated that ZM241385 had low exposure in rats. The results of semi-mass balance studies and the in silico PBPK modeling studies suggested that the low bioavailability of ZM241385 after oral administration in rats was due to the metabolism and by liver, kidney, and gut.
As interest in skin increases, the cosmetic market is also growing. It is difficult to choose between the numerous types of basic cosmetics on the market. This article aims to provide advice and ...guidance on which products to recommend according to a patient’s skin condition. Appropriate application of a moisturizer attempts not only to improve the dryness, but also improve the skin’s natural barrier function to protect the skin from internal and external irritants to keep the skin healthy. Moisturizers consist of various ingredients, including occlusive agents, emollients, humectants, lipid mixture, emulsifiers, and preservatives. Pathophysiology of dry skin is also discussed to provide readers with the background they need to choose the right moisturizer for themselves. As moisturizers play an important role as adjuvant in the treatment of common skin diseases, such as atopic dermatitis, contact dermatitis, psoriasis, acne and rosacea, which type of moisturizer is appropriate for each disease was also dealt with. Basic cosmetics, especially moisturizers, should be recommended in consideration of the ingredients, effectiveness and safety of each product, and the skin condition of each patient.
Daporinad (FK866) is one of the highly specific inhibitors of nicotinamide phosphoribosyl transferase (NAMPT) and known to have its unique mechanism of action that induces the tumor cell apoptosis. ...In this study, a simple and sensitive liquid chromatography-quadrupole-time-of-flight-mass spectrometric (LC-qTOF-MS) assay has been developed for the evaluation of drug metabolism and pharmacokinetics (DMPK) properties of Daporinad in mice. A simple protein precipitation method using acetonitrile (ACN) was used for the sample preparation and the pre-treated samples were separated by a C18 column. The calibration curve was evaluated in the range of 1.02~2220 ng/mL and the quadratic regression (weighted 1/concentration
) was used for the best fit of the curve with a correlation coefficient ≥ 0.99. The qualification run met the acceptance criteria of ±25% accuracy and precision values for QC samples. The dilution integrity was verified for 5, 10 and 30-fold dilution and the accuracy and precision of the dilution QC samples were also satisfactory within ±25% of the nominal values. The stability results indicated that Daporinad was stable for the following conditions: short-term (4 h), long-term (2 weeks), freeze/thaw (three cycles). This qualified method was successfully applied to intravenous (IV) pharmacokinetic (PK) studies of Daporinad in mice at doses of 5, 10 and 30 mg/kg. As a result, it showed a linear PK tendency in the dose range from 5 to 10 mg/kg, but a non-linear PK tendency in the dose of 30 mg/kg. In addition, in vitro and in vivo metabolite identification (Met ID) studies were conducted to understand the PK properties of Daporinad and the results showed that a total of 25 metabolites were identified as ten different types of metabolism in our experimental conditions. In conclusion, the LC-qTOF-MS assay was successfully developed for the quantification of Daporinad in mouse plasma as well as for its in vitro and in vivo metabolite identification.
5-Amino-7-(2-phenylethyl)-2-(2-furyl)-pyrazolo(4,3-e)-1,2,4-triazolo(1,5-c) pyrimidine (SCH 58261) is one of the new chemical entities that has been developed as an adenosine A
receptor antagonist. ...Although SCH 58261 has been reported to be beneficial, there is little information about SCH 58261 from a drug metabolism or pharmacokinetics perspective. This study describes the metabolism and pharmacokinetic properties of SCH 58261 in order to understand its behaviors in vivo. Rats were used as the in vivo model species. First, an LC-MS/MS method was developed for the determination of SCH 58261 in rat plasma. A GastroPlus™ simulation, in vitro microsomal metabolic stability, and bile duct-cannulated studies were also performed to understand its pharmacokinetic profile. The parameter sensitivity analysis of GastroPlus™ was used to examine the factors that influence exposure when the drug is orally administered. The factors are as follows: permeability, systemic clearance, renal clearance, and liver first-pass effect. In vitro microsomal metabolic stability indicates how much the drug is metabolized. The extrapolated hepatic clearance value of SCH 58261 was 39.97 mL/min/kg, indicating that the drug is greatly affected by hepatic metabolism. In vitro microsomal metabolite identification studies revealed that metabolites produce oxidized and ketone-formed metabolites via metabolic enzymes in the liver. The bile duct-cannulated rat study, after oral administration of SCH 58261, showed that a significant amount of the drug was excreted in feces. These results imply that the drug is not absorbed well in the body after oral administration. Taken together, SCH 58261 showed quite a low bioavailability when administered orally and this was likely due to significantly limited absorption, as well as high metabolism in vivo.
CADASIL is an inherited disease caused by mutations in the
NOTCH3
gene. We aimed to investigate the mutation and clinical spectrum, and genotype–phenotype correlations of Korean CADASIL patients. ...Samples from 492 clinically suspicious patients were collected from four hospitals. Sanger sequencing was performed to screen exons 2 to 25 of the
NOTCH3
gene and variants of unknown significance (VUS) were analyzed using the ACMG guidelines. The medical records and MRI data were received from each hospital, for comprehensive analysis of genotype–phenotype correlations. Previously reported
NOTCH3
variants were most commonly detected in exon 11 whereas exon 4 was the most common in European studies. The variants were detected equally between the EGFr domains 1–6 and 7–34, which was different from EGFr 1–6 predominant European studies. The average age-of-onset of patients with EGFr 1–6 variants were 4.81 ± 1.95 years younger than patients with EGFr 7–34 variants. Overall, it took Korean patients 51.2 ± 10 years longer to develop CADASIL in comparison to European patients. The most common mutation was p.R544C, which was associated with a later onset of stroke and a significant time-to-event curve difference. We verified four atypical phenotypes of p.R544C that had been reported in previous studies. Eight novel variants in 15 patients were detected but remained a VUS based on the ACMG criteria. This study reported a different EGFr distribution of Korean patients in comparison to European patients and its correlation with a later age-of-onset. An association between a later onset of stroke/TIA and p.R544C was observed.
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